With 1-Pyrenebutyric acid (PBA) and multiwalled carbon nanotubes (MWNTs), glassy carbon electrode modified was successfully prepared. In phosphate buffer solution (pH 7.0), the direct electrochemistry of cytochrome C (Cyt C) was realized. In the cyclic voltammetry experiment two pairs of redox peaks of Cyt C were observed at 0.018 V and -0.314 V (vs. SCE),respectively. The redox reaction at 0.018 V was diffusion controlled, while the redox reaction at -0.314 V was adsorption controlled.